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Questions and Answers
Which of the following are members of the genus Leishmania? (Select all that apply)
Which of the following diseases is caused by Leishmania donovani?
What is the definitive host of Leishmania tropica?
Man
The amastigote form of Leishmania has a flagellum.
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The intermediate host for Leishmania donovani is the ______.
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What is the characteristic shape of the promastigote stage of hemoflagellates?
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Which of the following is NOT true about the tryptomastigote form of Trypanosoma?
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Match the type of Leishmania to the disease it causes:
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Study Notes
Hemoflagellates- Developmental Forms
- Amastigote: Found in macrophages, spherical or rounded, reproduces by binary fission, has a kinetoplast and axoneme.
- Promastigote: Basic form, pyriform (pear-shaped), with a kinetoplast at the anterior end, no undulating membrane, and a free flagellum.
- Epimastigote: Elongated extracellular stage, kinetoplast closer to the nucleus, flagellum runs alongside the body as a short undulating membrane.
- Trypomastigote: Elongated, spindle-shaped, central nucleus, kinetoplast at the posterior end, long undulating membrane, and a free flagellum.
Hemoflagellates- Polymorphism
- Amastigote: Round or oval, delicate cell membrane, single vesicular nucleus with a large central karyosome, kinetoplast at right angles to the nucleus, no flagellum
- Promastigote: Elongated, centrally-located nucleus, kinetoplast at anterior end, vacuole in front of kinetoplast, single free flagellum from blepharoplast, no undulating membrane.
Leishmania donovani
- Obligate intracellular parasite of reticuloendothelial cells (liver, spleen, bone marrow, lymph nodes) in humans and vertebrates.
- Amastigote: 5 by 3µm, oval to round, one eccentric nucleus, kinetoplast with blepharoplast, axoneme, and parabasal body, no flagellum.
- Promastigote: 9-15 µm, long and slender, one central nucleus, kinetoplast at anterior end, no undulating membrane, single anterior free flagellum.
- Disease: Kala-azar, Dum-Dum fever, or visceral Leishmaniasis
- Intermediate host: Sand fly
- Definitive host: Mammals
- Infection stage: Metacyclic promastigotes
Leishmania tropica
- Disease: Dry or urban cutaneous Leishmaniasis, oriental sore, Baghdad boil, Old world cutaneous Leishmaniasis, tropica sore.
- Amastigotes: Found in endothelial cells of cutaneous tissues, lymph nodes, ulcers.
- Promastigotes: Found in the gut of sandfly.
- Definitive host: Human
- Intermediate host: Female sand fly
- Reservoir host: Dog, cats, mice, etc.
Leishmania spp. - Life Cycle
- Leishmania donovani causes visceral Leishmaniasis.
- Leishmania tropica causes cutaneous Leishmaniasis.
- Leishmania braziliensis causes mucocutaneous Leishmaniasis.
- Life Cycle: Transmitted by the bite of sandflies ( Phlebotomus).
- Promastigote Stage: Injected into the skin of the vertebrate host by infected female sandflies.
- Amastigote Stage: Promastigotes are engulfed by macrophages and transform into amastigotes, which multiply by binary fission.
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Description
Test your knowledge on the various developmental forms of hemoflagellates, including amastigote, promastigote, epimastigote, and trypomastigote. This quiz will challenge your understanding of their structures, characteristics, and stages in life cycles. Perfect for students of parasitology and microbiology.
